Electromagnetic vibrating device



March 5, 1929. T. H. NAKKEN ELECTROMAGNETIC VIBRATING DEVICE Filed May1926 2 Sheets-Sheet March 5, 1929. T. H. NAKKEN ELECTROMAGNETICVIBRATING DEVICE Filed May 1926 2 Sheets-Sheet IN E/VTOR x/4 H a Aim A Vw ATTORNEYS Patented Mar. 5, 1929.

UNITED STATES PATENT OFFICE.

'rnnonoiws n. NAKKEN, or JERSEY CITY. NEW JERSEY, ASSIGNOR TO mum. num-TENBEBG AND MEYER NATHAN LEIBOWITZ, on NEW YORK, 11. Y.

ELECTROMAGNETIC VIBRATING DEVICE.

Application filed May 3,

This invention relates to electromagnetic devices for effectingvibrations in accordance with variations of an electric current.

Mechanisms of this kind for. eiiecting the vibration of a single member,such as a diaphragm of a telephone receiver or of a loud speaker forwireless telephony, are well known, and comprise, for instance, anarmature pivotally mounted between double pole pieces of a magnet, sucharmature either being associated with a coil, through which the electriccurrent flows, in which case the magnet is of the permanent variety, orbeing in the form of a permanent magnet, in which case the magnet,between the pole pieces of which such armature is mounted, is associatedwith a coil through which the electric current flows, so that themagnetization thereof will vary according to the variation in thestrength of the cur rent.

The object of the present invention is to provide a device of this kindwhich is especially adapted for imparting vibrations to a plurality ofmembers, such as, for instance, the cone of a loud speaker for wirelessreceivers or the like, and the diaphragm of a horn which may be combinedin a single unit with such cone.

This application of the device, however, is given merely by way ofexample, since the device could be used for other purposes thanoperating two diaphragms associated together in a loud speaker.

The device, according to the present invention, comprises a plurality ofpivoted armatures extending between the poles of a magnet, and a coil orcoils connected in the circuit of said electric current, associated withsuch device, and adapted to control the magnetic interaction between thearmatures and the poles of the magnet.

In order that the invention may be clearly understood, reference is madeto the accompanying drawings which illustrate by way of example, threeembodiments of my invention, and in which Figure 1 is a. diagrammaticview in elevation of one form of the device;

Figure 2 is a diagrammatic view in plan of the armatures of this device;

Figure 3 is a diagrammatic view in elevation of a. modified form of thedevice;

1926. Serial No. 106,372.

Figure 4 is a diagrammatic view in elevatron of a further modified formof the device;

Figure 5 is a plan view of a preferred form of the invention;

Ifigure 6 is a front elevation of this form; and

Figure is a sectional elevation taken on line VII-VII of Figure 6.

Referring to Figures 1 and 2 of the draw-- in gs, a is a magnet whichmay be an electro-- magnet excited by a constant current, or a permanentmagnet. The poles of this mag-- net, as clearly shown in Figure 1, arebifurcated, thereby forming two upper poles b 6 of one polarity, and twolower poles 0 c of the other polarity. Two armatures (Z (Z arefloatingly held side by side between the poles of the ma net, with theirends extending respectively %etween the pole pieces 6 0 and b 0 Themounting of the two armatures preferably comprises a fiat spring 6extending transversely of the armatures and attached to them in anysuitable manner intermediate their ends. The ends of the flat spring 6are anchored in anv suitable manner, but preferably in a bobbiii f orthe like, surrounding the centre portions of the two armatures, and uponwhich is wound a coil 9 through which the variable electric current isadapted to flow.

The two armaturcs extend longitudinall side by side, but are separatedfrom eac other a slight distance, so that. there will be no frictionalcontact between them. One end of each armature extends beyond the polepieces, and to such extensions are connect d rods 72), if, which arealso connected respee--- tively to the members to which vibrations areadapted to be imparted. The rods or the like h, if, may be connectedrespectively at opposite sides of the device or at the same side of thedevice.

\Vhen the varying current flows through the coil g, the armatures d (1will be magnetized, the magnetization thereof varying according to thestrength of the current. Owing to the variation in the magnetization ofthe armatures, interaction between the ends thereof extending betweenthe pole pieces will vary, and the armatures will vibrate in accordancewith the variations in the strength of the current flowing through thecoil 9.

These vibrations will be transmitted by means of the rods 71. if, to themembers which are to be vibrated.

Referring to Figure 3 of the drawings, the two armatures al dillustrated therein, are mounted end to end instead of side by side, andtheir ends extend between the triple pole pieces of the poles of themagnet a. In such a construction, of course, each armature is mountedupon a separate spring 0 e and each is influenced by a separate coil g 9which may be connected in series or parallel.

Figure 4 illustrates a further development of the idea embodied inFigure 3. In the construction according to this figure, the central polepieces 6 c of the construction aeeording to Figure 3 are substituted bydouble pole pieces b, 6 and 0, 0 Otherwise, the two constructions arethe same.

The construction illustrated in Figures 5 to 7 of the drawings issubstantially the same as that illustrated in Figures 1 and 2 of thedrawing, but in this construction the parts have been assembled in amore compact form.

As clearly shown in these figures, the armatures d, a? are pivotallymounted between the poles of the permanent magnet by being connected tothe spring e, which is anchored at its ends, preferably as in the formerconstruction, in the bobbin f-upon which the coil g is wound. The rodsif, 713', are connected respectively to the armatures d d", on the sameside of the device. The permanent magnet a comprises the two pairs ofpole pieces 6 b and c 0 extending respectively downwardly and upwardlyfrom the bridge pieces is, Z, which extend in opposite directions, andare connected to the yoke m. Such magnet may be formed of a singlecasting, or the bridge pieces, with the pole pieces extending therefrom,may be bolted to the yoke piece m, or connected thereto in any othersuitable manner. A

By providing two diaphragms which can move independently of each other,the two members to be vibrated will be actuated without the vibrationsof one member affecting the vibrations of the other. This would not bethe case if the two members were connected to the opposite ends of asingle armature. since, with such a construction, there wouldnecessarily be interaction between the two members, owing to theirdirect connection with each other through the armature; and,consequently, each of such members would not have a separate naturalperiod of vibration, but the combined unit would have a natural periodof vibration, depending upon the individual natural periods ofvibration.

The construction according to the present invention entirely overcomesthis disadvantage, since the two members being allowed to vibrateindependently of each other, the natural period of vibration of eachwill not be effected. Consequently, if the device were used foroperating the diaphragm of a horn and the cone of a loud speakercombined in a single unit, the diaphragm and the cone would each bevibrated without the one acting as a load upon the other, and each wouldretain its normal characteristics.

As previously stated, however, the invention could be used for otherpurposes than the operation of the diaphragm of a horn and the cone of aloud speaker combined in a single unit.

The armatures, instead of being pivotally mounted intermediate theirends, may have their forward ends extending between the two poles of amagnet, and be pivotally mounted at their rear ends, such armaturesbeing floatingly held in an intermediate position between the poles bysprings or the like, or by being themselves of resilient material andhaving their rear ends anchored.

It is also obvious that further modification of the forms illustratedmay be devised without departing from the spirit and scope of theinvention as defined in the accompanying claims.

I claim- 1. An electromagnetic device for effecting vibrations in aplurality of members in accordance with variations in an electriccurrent comprising a plurality of armatures floatingly mounted betweenthe poles of a magnet, a single member to which both of such armaturesare connected and by which they are floatingly supported between saidpoles, and means associated with the circuit of said electric currentand associated with such device adapted to control the magneticinteraction between the armatures and the poles of the magnet.

2. An electromagnetic device for efl'ecting vibrations in a plurality ofmembers in accordance with variations in an electric current, comprisinga magnet having opposed poles, a plurality of armatures extending sideby side and floatingly mounted between said poles, means for floatinglysupporting such armatures between such poles and means associated withthe circuit of said current and associated with such device ada ted tocontrol the magnetic interaction etween the armatures and the poles ofthe magnet. 3. An electromagnetic device for effecting vibrations in aplurality of members in accordance with variations in an electriccurrent, comprising a plurality of armatures extending side by side,means for connecting said armatures to said members, a magnet havingopposed poles between which the armatures are floatingly supported,means for floatingly supporting said armatures between said poles, andmeans for magnetizing said armatures by said electric current wherebythe magnetization thereof will vary in accordance with the variations inthe electric current.

4. An electromagnetic device for effecting vibrations in a plurality ofmembers in accordance with vibrations in an electric current, comprisinga magnet having each pole divided into two pole pieces, a plurality ofarmatures extendin side by side, floatingly mounted between t e poles ofthe magnet, with their ends extendin between the opposed pole pieces,means or fioatingly sup porting such armatures between such pole pieces,and means for magnetizing said armatures in'accordance with thevariations in said electric current.

5. An electromagnetic device for effecting vibrations in a plurality ofmembers in accordance with vibrations in an electric current, comprisinga magnet having each pole divided into two pole pieces, a plurality ofarmatures mounted upon a sprin extending transversely of the armatures,and having its ends fixedly supported, such armatures extending side byside with their ends extendtending transversely thereof, and havin itsends anchored, such armatures havin t eir ends extending respectivelybetween t e opposed pole pieces of said magnet, and means associatedwith the circuit of said electric current and associated with suchdevice, adapted to control the ma etic interaction between saidarmatures an said pole pieces.

In testimony whereof I afiix my signature.

THEODORUS H. NAKKEN.

